Well perforating assembly



Oct. 22, 1963 B. M. CALDWELL ETAL 3,107,511

WELL PERFORATING ASSEMBLY Original Filed March 7, 1956 2 Sheets-Sheet 2 A A a 6 A a w z a w u 6 mm M. o 1 aw w 1 L w J mm? 7 1 a 5 M0 p A 6 k w w 26 6 w 1 r a ,A 9 1 M y a?! M 5 2; amy l/l B fie. 5.

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3,107,611 WELL PERFORATHJG ASSENELY Blake M. Caldwell and Harrold 1). Owen, Fort Worth, Tex., assignors to Haliiburton Company, Duncan, Old-a, a corporation of Deiaware Continuation of application Ser. N 570,004, Mar. 7, 1956. This application Feb. 7, 1961, Ser. No. 87,714

13 Claims. (Cl. 1102-20) This invention relates to well perforating means and more particularly to means for locking one or more perforating elements in a predetermined position during lower ing into a well and releasing same when within the well.

This application is a continuation of our copenoing application Serial No. 570,004, filed March 7, 1956, for Well Perforating Assembly, now abandoned.

In the completion of wells such as oil and gas wells drilled by the rotary method it has been the practice to perforate the casing adjacent the producing formation to admit oil and gas from the formation to the well. Such perforating has been done before the well was capped and while the drilling mud was in the casing. More recently however, the practice has been adopted of perforating after the tubing has been inserted into the well, the well head equipment affixed and the drilling mud removed. This latter method requires lowering through the relatively small tubing the perforating assembly to the vicinity of the producing formation and then perforating.

Various perforating assemblies have been developed for this type of perforating. A particularly effective type maintains the perforating units in vertical alignment during lowering through the tubing and permits the units to pivot upon emergence from the tubing to a horizontal firing position such as disclosed in W. H. Thompson et al. Patent No. 2,543,814, issued March 6, 1951, on Means and Method of Tilting Explosive Charges. An improvement on this type of assembly which provides for the retraction of the assembly after emergence from the tubing is described in an application for United States Letters Patent filed February 19, 1954 by Blake M. Caldwell and Joe P. Wier, Serial No. 411,349, entitled Tilting Charge Well Perforating Assembly, now Patent No. 3,067,678. A further improvement upon such an apparatus resides in controlling the pivoting of the perforating units from the ground surface and also in guarding against unexpected firing of the units as described in an application for United States Letters Patent filed October 8, 1954, by Blake M. Caldwell and Harrold 1). Owen, Serial No. 461,236 entitled Well Perforating Assembly, now Patent 3,067,679. It is with improvements in the apparatus disclosed in this latter application that the instant invention is particularly concerned.

In such an apparatus there is provided a firing head having an elongated carrier suspended therefrom. A plurality of pivotally mounted perforating units are mounted in the carrier biased towards a horizontal position but interlocked in a vertical position. Means are provided to release the interlock to permit pivoting of the units, and such latter mentioned means are actuated from the surface. As set forth in the latter mentioned application the firing circuit for the individual perforating units cannot be completed until the interlock has been released and the units pivoted to their firing positions.

It is, therefore, an object of this invention to provide means operable from the surface to release interlocked perforating units to permit them to pivot to a firing position.

It is a further object of this invention to provide such means which are guarded from injury or accidental actuation upon lowering of the assembly into the well.

It is still a further object of this invention to provide such means whereby foreign matter encountered during lowering of the assembly into the well cannot contact or affect the operation of the releasing mechamsm.

Other objects and advantages will be readily apparent from the following description:

In the drawings:

FIGURE 1 is a front elevation of a perforating assembly embodying this invention having a portion of the carrier broken away.

FIGURE 2 is a longitudinal section of the release mechanism illustrating engagement with the lower perforating unit.

FIGURE 3 is a view similar to FIGURE 2 iilustrating the release of the perforating unit.

FIGURE 4 is a longitudinal section similar to FIG- URE 2 of a modified form of release mechanism.

FIGURE 5 is a view taken along line 55 of HG- URE 4.

FIGURE 6 is a section taken along line 6-6 of FIGURE 4.

FIGURE 7 is a longitudinal section similar to FIG- URE 2 of a further modification.

The perforating assembly generally comprises a firing head 10, supported from the surface by a conductor cable (not shown). The assembly is lowered through the tubing of the well which in turn is within the casing as is well known to those skilled in the art. Suspended from firing head 10 is an elongated carrier 12, through which is threaded a firing fuse 114* which passes adjacent the perforating elements, in this instance shaped charges 16. The charges are pivotally mounted within the carrier 12 as by pins 18 and each is biased to a horizontal position by a spring 20. During descent through the tubing, however, the charges are locked in axial disposition with respect to said carrier 12 by means of interlocking detents 22. Release means operable from the surface of the well engage the detent 22 of the bottom charge. Upon operation of said release means the detent 22 of the bottom charge is freed permitting the spring 20 to pivot same to a horizontal position. This pivoting of the bottom shaped charge breaks the interconnection between the detents 22 on the upper end of the bottom charge and lower end of the charge immediately above permitting similar pivoting thereof and thereby successively freeing each charge 416 in the carrier 12 to pivot to its firing position.

Additional control means are provided whereby the shaped charges may not be fired from the surface in the event they fail to assume the desired firing position for any reason such as for example, engaging an obstruction in the well. For this purpose a plunger 24 abuts the uppermost of the shaped charges 16 and is moved upwardly upon pivoting of this charge to the horizontal firing position. This movement of plunger 24 closes a suitable switch (not shown) in firing head 10, completing the arming of the device permitting firing of the firing fuse 14 and hence shaped charges 16.

The above description of the device is believed adequate for the present application, but a more detailed description may be found in the above-mentioned United States patent application Serial No. 461,236, now Patent No. 3,067,679. In any event, the instant invention is directed to the means employed for locking the shaped charges in axial alignment with the carrier during descent through the tubing and for releasing same from the ground surface when desired after lowering.

tents above described, all of the shaped charges are in the aligned position. The plunger is urged to a posiition out of engagement with the detent on the bottom shaped charge but is restrained against movement. An explosive element operable from, the surface of the well functions to eliminate the restraint against movement of the plunger, whereby it is moved out of abutment with the detent on the lower shaped charge and permits the shaped charges to pivot to the firing position. 7

The first embodiment of the invention is illustrated in FIGURES 1 through 3. The carrier 12 at its lower extremity 26 forms an opening to receive a'body 23 which in turn has an aperture 30 in its lower extremity, a cap 32 being secured within aperture 3t); The body 28 may be secured in the carrier 12'by any suitable means such as set screw 33. V

The body 28 and cap 32 define housing having a chamber 34, and a pair of bores 36 and 38 communicate chamber 34 with the carrier above body 28. Through bore 36 plunger 40 passes, the base 42 thereof bearing upon the upper face 44 of cap 32, and the tip 45 of the plunger projecting beyond the upper face 46 of body 28 and engaging the lower detent 22 of the lowest shaped'charge 16.

A coiled spring 48 surrounds plunger 49 within cham- I a roof of chamber 76 and the enlarged extremity 78 of the retainer shaft. A weak point groove 84 machined or otherwise is provided in said retainer shaft 68. When the blasting cap 54a is fired as in the prior embodiment, the retainer shaft 68 breaks at the weak point groove 84. Since such shaft secures, through the spring 48a, the body 70 and hence the plunger 74, the aforesaid breaking permits the plunger, through the action of gravity, to disengage from abutment with respect to the detent 22a. Thereafter the shaped charges 16:: are free to pivot.

In FIGURE 7 still a further embodiment of this invention is illustrated wherein like parts having "a similar function as in the previously described embodiments are given the same numerical description with the addition of the designation [2.

In this embodiment a plug is inserted into the lower hollow extremity of carrier 12b and is secured therein by any suitable means, the plug being provided with a bore 88 aligned with the longitudinal axis of the carrier. A plunger 90 fits within the bore and projects above the plug where it is engaged by detent 22b and locks the shaped charges 16b in axial alignment, as in the previous embodiments, until withdrawn.

The bore 88 is counter-bored to house a spring )2 surrounding plunger The lower extremity 94 of plunger 90 is of enlarged diameter and forms a shoulder 96 against which spring 92 bears, said spring likewise bearing against the shoulder 93 formed by the counterbore in her 34, said spring bearing againstthe roof of the chamber a and engaging bare 42 of the plunger, thus biasing the plunger, downwardly to tend to withdraw tip 45 from engagement with the detent 22. When cap 32 is secured within aperture as shown in FIGURE 2, however, it resists movement of the-plunger and holds same in elevated position whereby tip 45 engages detent 22. The cap 32 has a pair of recesses 50 and 52 which communicate with chamber 34, the recess 59 housing a blasting cap 54. Thecap is grounded by wire 56 and connected by wire 58 to the firing head 10 and hence to switch means at the ground circuit.

When the aforesaid switch is closed, the circuit through cap 54 is completed, exploding same. The explosion forces cap 32 downward from chamber 34 and may be sufficient to shatter the cap. This condition is best seen in FIGURE 3 which shows the device after detonation of the blasting cap 54. Spring 48 then urges the plunger 40 downwardly, releasing the detent 22 of the lower shaped charge and permitting the charges to successively pivot to the horizontal firing position, as previously described. a

In FIGURES 4 through 6 a modified form of this invention is illustrated wherein like parts having the same general function as in the previously described embodiment are given the same numerical designation, with the addition of the designation a. In this embodiment a plug'fl) is secured in the extremity of carrier 12a by any suitable means such as set screw 62. The plug has a bore 64 therethrough and a. second bore 66 which extends partially through the plug and communicates with the underside thereof. The bore 66 is threaded to receive the threaded extremity of retainer shaft 68.

A body 70 surrounds shaft 68 and has a bore 72 through which the shaft freely projects. The body 70 has suitably fixed upon its upper surface as by threading a plunger 74 which slidably projects through bore 64 and engages the detent'22a locking the shaped charges 16a in axial alignment with carrier 1211, as heretofore described. The body 70 has a chamber 76- formed therein which receives the lower extremity of the retainer shaft 68. The lower extremity of the retainer shaft is enlarged as at 78 and has a bore therein from the underside forming a blasting cap receiving chamber 80. The blasting cap 54a is retained in chamber 80 by a stopper 82 which is of rubber or other suitable material. Surrounding the retainer shaft 68 is a spring 48a which bears against the.

the plug 86, urging the plunger downwardly.

To hold the plunger in its upper detent abutting position the plug 86 is provided with a cross-bore 10%) intersecting the bore 83. Likewise, the plunger 90 in its enlarged end 94 has a cross-bore- 102 which is axially aligned with the bore 1% and which receives the blasting cap 541). Thus the cap, which projects through the bore 102 in plunger 90 and into bore 100 on either side of the plunger, holds the plunger against the force of spring 92. When the cap is exploded by completing the circuit through wire 53!) the spring 92 forces the plunger downwardly, the obstruction to its movement having been removed, releasing the detent 22b and thus the charges 16b for pivotalmovement.

Thus in operation in each of the embodiments a plunger abuts the bottom detent of the lowest shaped charge retaining all of the chargesinaxial alignment with the carrier. When the. detonating cap is fired from the surface of the well, the obstruction restraining the plunger from movement is removed. The plunger then moves to a detent freeing position permitting successive pivoting of the shaped charges to the firing position.

'While what hereinbefore has been described are the preferred embodiments of this invention, it is apparent that alterations and modifications can be resorted to without departing from the scope of this invention and such alterations and modifications are intended to be included within the appended claims.

We claim:

1. In a well perforating assembly for a shaped charge pivotally mounted within a carrier, the combination of: a carrier; a shaped charge pivoted to said carrier; a plug insertable into said carrier; a plunger within said plug abutting said shaped charge resisting pivoting thereof, said plunger being urged from abutment with said shaped charge to permit pivoting of said shaped charge; and a blasting cap and means for firing the same, said blasting cap securing said plunger in the shaped charge abutting position and eliminableupon being fired to release said plunger for movement from abutment with said shaped charge.

spring surrounding said plunger urging same to move to a V position out of abutment with respect to said shaped charge to permit pivoting of the latter; a blasting cap in said plug, said blasting cap resisting movement of said plunger and eliminable upon being fired to release said plunger for movement from abutment with said shaped charge; and means for firing said blasting cap.

3. In a well perforating assembly for a shaped charge pivotally mounted within a carrier, the combination of: a carrier; a shaped charge pivoted to said carrier; a plug insertable into said carrier having a pair of intersecting bores therein; a plunger in one of said bores abutting said shaped charge resisting pivoting thereof, said plunger being urged from abutment with said shaped charge to permit pivoting of the latter; a blasting cap in the other bore, said blasting cap holding said plunger in the shaped charge abutting position and eliminable upon being fired to release said plunger for movement from abutment with said shaped charge; and means for firing said blasting can.

4. In a well perforating assembly for a shaped charge pivotally mounted within a carrier, the combination of: a carrier; a shaped charge pivoted to said carrier; a plug insertable into said carrier having a pair of intersecting bores therein; a plunger in one of said bores abutting said shaped charge resisting pivoting thereof; a blasting cap in the other bore, said blasting cap holding said plunger in the shaped charge abutting position and eliminable upon being fired to release said plunger for movement from abutment with said shaped charge to permit pivoting of the latter; means for firing said blasting cap; and spring means urging said plunger out of abutment with respect to said shaped charge.

5. In a well perforating assembly, the combination of: a carrier; a shaped charge unit pivotally mounted on said carrier to pivot to a different position; first resilient means urging said unit to pivot to said different position; first detent means fixedly mounted on said unit; elongated second detent means mounted on said carrier and abutting said first detent means to restrain said unit from pivoting to said different position, said second detent means being mounted for movement longitudinally of itself from abutment with said first detent means; second resilient means urging said second detent means to move from abutment with said first detent means; a restraining member preventing movement of said second detent means; a charge of explosive material adapted upon being fired to eliminate said restraining member to permit movement of said second detent means from abutment with said first detent means, whereby said unit may pivot to said different position; and means for firing said charge of explosive material.

6. In a well perforating assembly, the combination of: a carrier; a shaped charge unit pivotally mounted on said carrier to pivot to a different position; first resilient means urging said unit to pivot to said different position; first detent means fixedly mounted on said unit; elongated second detent means mounted on said carrier and abutting said first detent means to restrain said unit from pivoting to said different position, said second detent means being mounted for movement longitudinallly of itself from abutment with said first detent means; second resilient means urging said second detent means to move from abutment with said first detent means; a restraining member acting between said carrier and said second detent means preventing movement of said second detent means; a charge of explosive material adapted upon being fired to eliminate said restraining member to permit movement of said second detent means from abutment with said first detent means, whereby said unit may pivot to said diiferent position; and means for firing said charge of explosive material.

7. In a well perforating assembly, the combination of: a carrier; a shaped explosive charge unit pivotally mounted on said carrier to pivot to a different position; first resilient means urging said unit to pivot to said different position; detent means fixedly mounted on said unit; a plunger mounted on said carrier and abutting said detent means to restrain said unit from pivoting to said different position, said plunger being mounted for movement from abutment with said detent means; second resilient means urging said plunger to move from abutment with said detent means; a restraining member acting between said carrier and said plunger preventing movement of said plunger; a charge of explosive material adapted upon being fired to eliminate said restraining member to permit movement of said plunger from abutment with said detent means, whereby said unit may pivot to said different position; and means for firing said charge of explosive material.

8. In a well perforating assembly, the combination of: a carrier; a shaped explosive charge unit pivotally mounted on said carrier to pivot to a different position; first resilient means urging said unit to pivot to said different position; detent means fixedly mounted on said unit; a housing inserted in said carrier; a plunger mounted in said housing and abutting said detent means to restrain said unit from pivoting to said different position, said plunger being mounted for movement from abutment with said detent means; second resilient means acting between said plunger and said housing urging said plunger to move from abutment with said detent means; a restraining member acting between said housing and said plunger preventing movement of said plunger; a charge of explosive material in said housing adapted upon being fired to eliminate said restraining member to permit movement of said plunger from abutment with said detent means, whereby said unit may pivot to said different position; and means for firing said charge of explosive material.

9. In a well perforating assembly the combination of: a carrier; a shaped explosive charge unit pivotally mounted on said carrier to pivot to a different position; first resilient means urging said unit to pivot to said different position; detent means fixedly mounted on saaid unit; a housing inserted in said carrier, said housing having a pair of intersecting bores; 21 plunger mounted in one of said bores and abutting said detent means to restrain said unit from pivoting to said different position, said plunger being slidable in said one bore from abutment with said detent means; second resilient means acting between said plunger and said housing urging said plunger to slide from abutment with said detent means; a blasting cap in the other bore of said housing holding said plunger in abutment with said detent means, said blasting cap being adapted to be eliminated upon firing to permit said plunger to slide from abutment with said detent means, whereby said unit may pivot to said different position; and means for firing said blasting cap.

10. In a well perforating assembly, the combination of: a carrier; a shaped charge unit pivotally mounted on said carrier to pivot to a different position; resilient means urging said unit to pivot to said different position; first detent means fixedly mounted on said unit; elongated second detent means mounted on said carrier and abutting said first detent means to restrain said unit from pivoting to said different position, said second detent means being mounted for movement longitudinally of itself and being urged to move from abutment with said first detent means; a restraining member preventing movement of said second detent means; a charge of explosive material adapted upon being fired to eliminate said restraining member to permit movement of said second detent means from abutment with said first detent means, whereby said unit may pivot to said different position; and means for firing said charge of explosive material.

11. In a well perforating assembly, the combination of: a carrier; a shaped charge unit pivotally mounted on said carrier to pivot to a different position; resilient means urging said unit to pivot to said difierent position; detent means fixedly mounted on said unit; a plug inserted into said carrier, said plug having a bore therethrough; a body; a plunger on said body projecting through said bore, said plunger abutting said detent means to restrain said unit from pivoting to said difierent position, said plunger and body being adapted for movement together and being mounted for movement and being urged to move said plunger from abutment with said detent means; a restraining member securing said body to said plug, preventing movement of said plunger and body; a charge of explosive material adapted upon being fired to break said restraining member 'to permit movement of said plunger and body with movement of said plunger from abutment with said detent means, whereby said unit may pivot to said different position; and means for firing said charge of explosive material.

12. In a well perforating assembly, the combination of:

a carrier; a shaped charge unit pivotally mounted on said carrier to pivot to a different position; resilient means urging said unit to pivot to said diiferent position; detent means fixedly mounted on said unit; a body inserted into said carrier; a cap inserted into said body and defining with said body a chamber; a plunger having an extremity abutting said detent means to restrain said unit from pivoting to said different position, the other extremity of said plunger being Within said chamber, said plunger being mounted for movement from abutment with said detent means; spring means Within said chamber urging said plunger to move from abutment with said detent means; a portion of said cap abutting said other end of said plunger preventing movement of said plunger; an explosive element including a charge of explosive material adapted upon being fired to eliminate said cap to permit movement of said plunger from abutment with said detent means, whereby said unit may pivot to said different position; and means for firing said charge of explosive material. 7

13. In a method of perforating a Well in which a string of tubing is suspended in the well bore wherein a shaped explosive charge unit is lowered through said tubing and into the Well bore below the bottom of the tubing with the unit disposed with its jet axis vertical and its jetforming end down and is biased to pivot to a position wherein the jet axis is transverse to the Well bore and the jet-forming end is directed towards the Wall of the well bore, the improvement which comprises: restraining 'said unit in said vertical disposition by means of a first References Cited in the file of this patent FOREIGN PATENTS 1,029,798 France Mar. 11, 1953 

1. IN A WELL PERFORATING ASSEMBLY FOR A SHAPED CHARGE PIVOTALLY MOUNTED WITHIN A CARRIER, THE COMBINATION OF: A CARRIER; A SHAPED CHARGE PIVOTED TO SAID CARRIER; A PLUG INSERTABLE INTO SAID CARRIER; A PLUNGER WITHIN SAID PLUG ABUTTING SAID SHAPED CHARGE RESISTING PIVOTING THEREOF, SAID PLUNGER BEING URGED FROM ABUTMENT WITH SAID SHAPED CHARGE TO PERMIT PIVOTING OF SAID SHAPED CHARGE; AND A BLASTING CAP AND MEANS FOR FIRING THE SAME, SAID BLASTING CAP SECURING SAID PLUNGER IN THE SHAPED CHARGE ABUTTING POSITION AND ELIMINABLE UPON BEING FIRED TO RELEASE SAID PLUNGER FOR MOVEMENT FROM ABUTMENT WITH SAID SHAPED CHARGE. 